Strict legislation in developed countries concerning the usage and disposal of many chemicals, during the last few decades, brought industrial innovations based on sustainable green processes and ...nature-based solutions, eliminating toxic wastes and opening the space for broader implementation of natural bioactive compounds and extracts. Thymol, a natural monoterpene with a broad spectrum of strong biological activities, began to be widely applied in science and industry, including the production of active food packaging materials. In this framework, this article provides a comprehensive review on the use of thymol for active food packaging, summarizing reported technologies and explaining the impact of its addition on the thermal, structural, mechanical, and barrier properties of polymeric films. Moreover, this review analysis effects of films’ physical properties on the release of thymol and revises the strategies to tune the release kinetics. It also provides a critical and comprehensive analysis of the published data on the antimicrobial properties of active films containing thymol. Based on the presented data, knowledge gaps were identified, and possible research trends were discussed. The analysis of the presented technologies showed that supercritical solvent impregnation might overcome the drawbacks of conventional processes, such as high thymol loss and its uneven distribution. The reviewed data indicated that bioactive polymeric materials containing thymol, especially PLA, might have applications in flexible and semirigid packaging because of the improvement of polymer ductility. As a successful strategy of tunning thymol’s release kinetics, its inclusion into structures such as cyclodextrins and metal-organic frameworks is identified. Finally, it was shown that the antimicrobial activity of the active food packaging and thymol’s diffusivity varied significantly depending on the applied technology, the nature of the polymer, and other added compounds.
•Update of the biopolymers and synthetic films used to design thymol-based films.•Supercritical impregnation may overcome drawbacks of conventional technologies.•Unveiled thymol effects on the physical properties of biopolymer/synthetic films.•Thymol release tuning is possible by its inclusion in structures such as CDs and MOFs.•Antimicrobial activity varied with the applied technology and polymer nature.
In East Africa,
(L.f.) is a well-known medicinal herb. Its leaf is primarily studied in light of its ethnobotanical use. In terms of phytochemistry and biological activity, its flower is not studied. ...In a prior study, our team looked into phytochemical screening, antioxidant activity, and total phenolic levels. This study aims to compare the profiles and biological activities of the leaf and flower samples of
and to present therapeutic alternatives. The leaf and flower sample powders were extracted with methanol using ultrasound-assisted extraction (UAE). HPTLC profile was obtained using CAMAG-HPTLC equipped with VisionCATS software. Antimicrobial agar well diffusion assay and minimum inhibition concentration (MIC) were determined. The leaf and flower extracts of
showed antibacterial activity with a MIC value of 20 µg/mL against
and
. Similarly, 40 µg/mL was found to be effective against
.
flower is a rich source of flavonoids and phenolic acids. Because of its antibacterial properties and profile, which are almost the same, the flower is emerging as a viable option for medicinal alternatives.
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•Phenolic composition of black, red and white quinoa grains was evaluated.•Quercetin and kaempferol derivatives were present in all quinoa varieties.•None of the quinoa varieties ...showed toxicity in hepatotoxocity assay.•All hydroethanolic extracts possessed antibacterial and antifungal activity.
The ingestion of bioactive compounds has revealed health benefits, namely in the prevention and/or treatment of several diseases. This work aims to characterize the phenolic profile of three colour varieties of Chenopodium quinoa Willd. grains (black, red and white), and also evaluate their cytotoxic and antimicrobial activity. All varieties revealed the presence of phenolic compounds, namely, quercetin and kaempferol derivatives. In this study, quinoa grains did not reveal any anti-proliferative capacity in tumour cell lines, and, as expected, they were devoid of any toxicity. All of the analysed extracts possessed antibacterial and antifungal activities (inhibitory and bactericidal/fungicidal) against the microbial strains considered, exhibiting promising values of minimum bactericidal concentrations (mean MBC 0.153–0.916 mg/mL) and minimum fungicidal concentrations (mean MFC 0.211–0.884 mg/mL). Quinoa varieties represent a good source of bioactive compounds, interfering beneficially in the organism, specifically as antimicrobial agents. Thus, these extracts could be used in the development of bioactive ingredients.
•Green synthesis of AgNPs nanoparitcles using Hardwickia binata.•The synthesized AgNPs were characterized by UV, XRD, IR, FE-SEM-EDAX, and HR-TEM with SAED pattern.•The synthesized AgNPs shows a ...Spherical shape of nanoparticles.•The synthesized AgNPs demonstrated excellent biological & photo-catalytic activities.
In this study, synthesized AgNPs were produced using an aqueous leaf extract of Hardwickia binata. The highest absorption wavelength was found to be at 454 nm. The study evaluated the antibacterial activity of the synthesized AgNPs and found that they exhibited the highest zone of inhibition against B. subtilis, indicating good antibacterial activity. The antioxidant activity evaluated using DPPH, ABTS assays and further analyzed the synthesized AgNPs for their anti-inflammatory and anti-proliferative activity. In an environmental related study, the degradation of Methylene Blue (MB) dye using the synthesized AgNPs. The results showed that the MB dye was completely degraded within 210 min, suggesting that the synthesized AgNPs have potential as treatment option for dye-containing wastewater. The findings of the study synthesized AgNPs the antioxidant, anti-inflammatory, anticancer and good dye degradation properties. The current research holds promise for addressing the issue of removing hazardous dyes from wastewater discharged by many industries.
Aims
Since mycosynthesis of metal nanoparticles (NPs) is advertised as a promising and ecofriendly approach. Thus, this study aims to investigate the capability of Aspergillus brasiliensis ATCC 16404 ...for mycosynthesis of silver NPs (AgNPs).
Methods and Results
One‐factor‐at‐a‐time‐technique was used to study the effect of different physicochemical parameters: the reaction time, pH, temperature, different stirring rates, illumination, and finally, the different concentrations of silver nitrate and fungal biomass on the mycosynthesis of AgNPs. The visual observation showed the characteristic brown colour formation due to the bioreduction of Ag+ ions to Ag0 by the mycelial cell‐free filtrate (MCFF). The UV/visible spectrophotometric technique displayed a characteristic sharp peak at ʎ440 confirming the mycosynthesis of AgNPs. The zeta potential value −16·7 mV assured the long‐term stability of AgNPs and the dynamic light scattering analysis revealed good dispersion and average particle size 77 nm. The energy dispersive X‐ray spectroscopy displayed a maximum elemental distribution of silver elements. The X‐ray diffraction spectroscopy demonstrated the crystallinity of the mycosynthesized AgNPs. The field emission scanning electron microscope and high‐resolution transmission electron microscope revealed monodispersed spherical shaped AgNPs with average particle size of 6–21 nm. The FTIR analysis showed the major peaks of proteins providing the possible role of MCFF in the synthesis and stabilization of the AgNPs. The mycosynthesized AgNPs expressed good biocidal activity against different pathogenic micro‐organisms causing some water‐related diseases and health problems to local residents.
Conclusions
This study proved that A. brasiliensis ATCC 16404 MCFF has good potential for mycosynthesis of AgNPs, which exhibited good antimicrobial effect on different pathogenic micro‐organisms; thus, it can be applied for water disinfection.
Significance and Impact of the Study
This research provides a helpful insight into the development of a new mycosynthesized antimicrobial agent.
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•An intravascular catheter was coated with CMC layer exhibiting antimicrobial, antithrombotic, and low friction properties.•Whole manufacturing process was water-based, hence ...eco-friendly and biocompatible.•Functionalities of CMC layer were enhanced by engineering the porous structure.•Sufficient lubricity of porous CMC coated catheter was verified via trackability test.
Antimicrobial, antithrombotic activity and low-friction functions are essential for the surface of intravascular catheters (ICs). However, the multifunctional surface, encompassing all of the above properties has not yet been realized. Here, we report a novel strategy for biocompatible and eco-friendly surface modification of the ICs with multifunctional polysaccharide, O-carboxymethyl chitosan (CMC). Micro- and nanoscale porous CMC (p-CMC) layer was simply fabricated via a selective elimination of the water-soluble polyethylene glycol (PEG) from heterogeneous CMC/PEG composite. The p-CMC structure exhibited a significantly enhanced hydration rate and superhydrophilic property. In particular, the antifouling property of superhydrophilic surface showed excellent anti-adhesion of Escherichia coli and platelets along with the intrinsic multifunctionality of CMC, indicating a dual effect of our p-CMC layer: (1) intrinsic antibacterial and antithrombotic properties of CMC and (2) anti-adhesion of substances on superhydrophilic surface. Meanwhile, despite the rough surface of the p-CMC layer, it showed high lubricity and durability under continuous wet friction conditions. Furthermore, we demonstrated that the actual p-CMC coated intravascular catheter (IC) provides superior trackability in a curved artificial blood vessel. The potential of the proposed coating strategy can be offered not only ICs, but also wide range of polymer-based applications including vascular filters, grafts, pacemakers and soft robots.
•RSM was used for optimization of pepper seed oil microencapsulation.•NMR and FTIR spectroscopy proved a successful microencapsulation.•High thermal stability could supply great advantages to pepper ...seed oil powder.•GA as coating material provided antimicrobial activity to pepper seed oil.•Oxidative stability of pepper seed oil was increased by GA/MD microencapsulation.
In this study, pepper seed oil (PSO) was microencapsulated by spray drying at optimum conditions: oil/total solid material at 20% (w/w), gum Arabic/maltodextrin (GA/MD) at 1/5 (w/w), and air inlet temperature of 184 °C. Particle size distribution and morphology of the PSO powder (PSOP) were determined by a laser particle diameter analyzer and scanning electron microscopy (SEM). Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) were employed to identify the specific chemical groups of PSO, MD, and GA in the PSO-GA/MD complexes. The thermal stability of PSOP was evaluated by thermogravimetric (TGA) and differential thermal analysis (DTA). PSOP displayed inhibitory activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis although PSO had an antimicrobial activity against only Staphylococcus aureus. GA/MD microencapsulation resulted in significant preservation of PSO against oxidation during storage period.
A novel series of mixed‐ligand complexes of 5,5′‐{(1E,1E′)‐1,4‐phenelynebis(diazene‐2,1‐diyl)}bis(quinolin‐8‐ol) (H2L1) as a primary ligand and 4‐aminoantipyrine(L2) as a secondary ligand with Mn(II) ...ion were prepared using two general formulae: Mn2(H2L1)2(L2)2X4.4Cl (X = OH2(1), ONO2−(2), Cl=nil; OAc(3), Cl = nil) and Mn2(H2L1)(L2)2(O2SO2)2(4). Free ligands and their complexes were characterized. Electronic absorption spectra of the mixed‐ligand complexes indicate a distorted octahedral geometry around the central metal ion, and the anions X− are in the axial positions for all compounds. The ligands behave in a neutral bidentate manner, through nitrogen atoms and oxygen atoms of the carbonyl group (L2), whereas H2L1 coordinated through nitrogen and OH groups as a neutral bidentate ligand. All complexes do not contain coordinated water molecules, but complex (1) contains four water molecules. The water molecules are removed in a single step. The complexes exhibited magnetic susceptibility corresponding to five unpaired electrons. The antimicrobial activity of the Mn(II) mixed‐ligand complexes (1–4) against two gram‐positive bacteria, three local gram‐negative bacteria, and three fungi species was tested. Mn(II) mixed‐ligand complex (2) exhibited significant antibacterial activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas sp. Mixed‐ligand complex (2) exhibited a high potential cytotoxicity against the growth of human lung cancer cells.
The treated cells of Bacillus cereuswith Mn(II) mixed‐ligand complex(2) (A and B; control, C and D; Bacillus cereus affected with DMF, E and F; Bacillus cereus affected with complex) revealed that almost all cells were lysed and void of cytoplasmic fluid with completely shrinkage of cytoplasmic membrane (F), also the presence of an increase in vacuolization and corresponding disorganization of the cytoplasm was observed (E). The cells treated with DMF were observed slightly visible alterations (C and D).
This research is mainly focused on preparing gallic acid (GA) coated, antimicrobial, active packaging, low density polyethylene (LDPE) films by capacitively coupled plasma. Firstly, the suitable ...plasma treatment condition was 30 W treated for 60 s from the result of appearance and tensile strength. From the result of SEM and ATR-FTIR, the surface roughness increased which facilitated the GA coating and the surface turn smoother after GA coating. In the result of antimicrobial activity, these films is able to reduce the growth of Gram-negative bacterium Escherichia coli and Gram-positive bacterium Staphylococcus aureus about 0.5–0.6 log CFU/mL when GA concentration is above 1%. Between these two microorganisms, the film has more significant inhibition on E. coli than S. aureus due to cell membrane structure differences. These results are first stage in developing antibacterial active packaging for foods preservation.
•This is the first study of gallic acid-coated polyethylene film by using plasma treatment.•ATR-FTIR result shows the bonding between gallic acid and polyethylene.•Growth of microorganisms are inhibited when the concentration is 1% or above.
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